CONTENTS. 



PAGE 



Introduction 7 



I. THE DAILY MAHCH OF STOMATAL MOVEMENT 18 



The daily movement in alfalfa 18 



The daily movement in potato 27 



The daily movement in sugar-beet 33 



The daily movement in onion 37 



The daily movement in cereals 39 



Discussion of results 45 



Summary 48 



II. EFFECT OF PHYSICAL FACTOKS AND PLANT CONDITIONS UPON STOMATAL MOVEMENT 50 



Light 50 



Temperature 56 



Evaporation and oausal factors 59 



Water-content 66 



Leaf turgor 68 



Plant habit and condition 71 



Summary 74 



III. EFFECT OF STOMATAL MOVEMENT UPON TRANSPIRATION 77 



Summary 101 



BIBLIOGRAPHY . . 103 



